204 Syslenuitic Position q/' Macii.stiiim cliavesi. 



30. 1 20 mm. Onon R. Godeffioy Mus. 



31-32. 100-105 mm. Inland Sea of Japan. R. Gordon Smith, 



[Esq. 

 33-42. 80-100 mm Gifu, Mino Prov., Japan. Prof. Mitsukuri. 



Ammocates branchialis, Linn. 



Under this name may be placed a number of larvge, most 

 of which probably pertain to Lampetra, but some to other 

 Petromyzonids. 

 1. Tweed. 



XIX. — On the Systematic Position o/" Macristium cliavesi. 

 By C. Tate Regan' M.A. 



In 1903 (Ann. & Mag. Nat. Hist. (7) xii. p. 345) 1 described 

 a remarkable fish from the Azores, to which I gave the name 

 Mncristium cliavesi. Recently, when working at the osteology 

 and classification of the Iniomi, it seemed to me desirable to 

 re-examine this fish ; I accordingly wrote to Major ¥. A. 

 Ciiaves, who has kindly sent me the specimen. 



The type of Macristium chavesi measures 110 mm. to the 

 base of tlie caudal fin ; it has been a good deal damaged, and 

 in the absence of precise information I should judge that it 

 may have been washed ashore. The snout and the end of 

 the lower jaw are injured and the prseniaxillaries have been 

 lost; one of the pectoral fins is complete, but none of the 

 other fins has even a single ray entire. 



Originally I believed that Macristium was related to 

 Bathysaurus, Giinth., which it resembles in the position of 

 the fins and the number of rays. I am now of the opinion 

 that this resemblance is misleading, for 1 think that in all 

 probability the prsemaxillaries would not exclude the max- 

 illaries from the gape. In any case, Macristium must be 

 made the type of a distinct family, Macristiidjie, probably 

 related to the Alepocephalida^. 



Before returning the fish to the Ponta Delgada Museum it 

 seems to me best to make a figure of it and to reinforce my 

 oii^^inal description. 



The body is elongate, moderately compressed, naked ; the 



